Why do I feel like this?

I feel like I settled I enjoy my life I have a good job my children are perfect and I have a roof over my head but I feel like I settled when it came to my partner but at least I know I have one and he is here to stay.

Before it all became serious my ex asked me do I wish I chose him and tbh o wanted to say maybe but I never really knew how he felt.

Why do I feel like this I want to be happy I am happy but sometimes o don’t feel it.